Pipe making machinery



S w-' 1932- L. CAMMEN a I 1,875,560

PIPE uxme MACHINERY Filed NOV. 17, 19 30 2 Sheets-Sheet 1 1' 2IINVENTOR. f 11% W P 1 CAMMEN 1,875,560

PIPE MAKING MACHINERY Filed Nov. 17. 1930 2 Sheets-Sheet 2 I N VEN TOR.

Patented Sept. 6, 1932 UNITED STATES.

PATENT OFFICE LEON CAMMEN, OF NEW YORK, N. Y.

PIIE.I.AKING MACHINERY ing the meeting edges of successive turns of thehelix'as, for example, by welding.

The present invention has for an objectto provide an improved method ofand means for forming a strip of metal into a helix to make a pipetherefrom.

- Another object is to provide an improved method and means for holdingthe successive turns of the helix in close engagement while uniting thesame.

Another object is to provide an improved method of and means forprogressively contacting the meeting edges of successive turns withsubstantial pressure and welding them at the point of pressure.

" Another object isto provide an improved arrangement for bending thesheet metal between bendin rolls.

Another ob ect is to provide means for first bending the sheet metal toform a helix of a size approximating that required for the final form ofthe pipe and thereafter further bending the sheet metal to final form.

The present invention provides an improved arangement comprising bendingrolls for forming a strip of sheet metal into the form of a helix ofslightl different size than that finally required or forming thepipe'and progressively closing the joint with substantial pressure atthe point of closing 35 and securing the contacting edges as by weld Thearrangement which comprises first forming the sheet metal into apreliminary helix and thereafter bending it to the final form ofi'ersfeatures of general advantage and is especially desirable when formingpipe from relatively heavy metal or from metal which is diflicult tobend by merely winding the same upon a mandrel.

The nature and objects of the invention will be better understood from adescription of a particular illustrative embodiment for the pu ose ofwhich description reference should he had to the accompanying drawingsforming a part hereof and in which the point where the welding actiontakes Application fled Rovember 17, 1930. Serial 1T0. 496,212.

Figure 1 isa sectional view of pipe formin apparatus embodying theinvention;

Fig. 2 is the same device as seen from below in outside view.

Fig. 3 shows several modifications of the guide 26 of Fig. 2;

Fig. 4 is a sectional view of the brake shown at 14 and 15 in Fig. 1

Fig. 5 is-an end view of the pipe including place.

Fig. 6 shows a more detailedsectional view of the rollers 4, 5, 3 and 6of Fig. 1

Fig. 7 shows a modification in the design of the rollers which may bealso used to take place of the brake shown in Fig. 4.

None of the machines for making spirally welded pipe built hitherto havemeans for producing pressure between the edges of the skelp meeting inthe seam where the weld takes place otherwise than between the outsidebending rolls. In the case of resistance welding, in particular, quite apowerful pressure, of the order of 6,000 to 8,000 lb. per sq. in. isrequired. Moreover, for resistance weldin this pressure must becarefully localized an extend only from the place previously welded tothe place where the metal is made plastic by the heat produced by theflow of the current. If there is rigid abutment ahead so of that place,the weld will not occur or will be poor. There is no machine for makingspirally welded pipe where this has been provided.

In this invention there is provided a mandrel 24 which is preferablystationary, to-

' gether with a roller or system of rollers preferabl supported frommandrel 24. These are s own-as 2, 3 and 4 in Fig. 6, and also, inanother view, in Fig. 1. There is also made provision for an outsideroller or system of rolls, such as 5, 6 and 7, with skelp 1 between theinside and outside rolls. Further a guide, such as 26, Fig. 1, isprovided, located within one of the seams of the coiled pipe.

When the power driven rolls 5, 6 and 7 start going, the followinghappens. In the first place the skelp 1 is given a motion of rotation,really winding, about rolls 2, 3 and 4. If no other machinery had beenprovided, the action would have been that of a coiler, there beingnothing to create a side motion. Because, however, of the presence ofguide 26, the skelp has'not only to turn around, but must move past theguide. The force that 5 makes the skelp slide sidewise is a component ofthe force produced between the outside and inside rolls. The magnitudeof this component depends entirely on the amount of riction producedbetween the edge of the skelp and guide 26, and for obvious reasons itis impractical to make this friction large; on the contrary, there is anadvantage in having it as small as possible, and yet a very largepressure is needed at the point of welding, 33, Figs. 1 and 2. When roll6 is running and there is a resistance to the motion of the skelp at 26,the tendency will be, first, to close up the seam at 33, and, next, tomove the skelp past 26. If the section of the skelp under 14 offeredsome resistance to motion, more force would have to be provided by therolls, such as 6, to cause the skelp to move at all, and hence therewould be more pressure at 33. This is accomplished b the provision ofbrake 1314, Fig. 4. his brake may consist of an inside roll or system ofrolls, such as shown for another purpose in Fig. 6, but may also consistof a working part of a roll, such as 15 in Fig. 4 on the inside, and anyof these stg'uctures on the outside, such as 14, with provision to varythe grip on the skelp 1 moving therebetween, which may be done bycounterweight 13, or similar means well own to-engineers.

The mandrel 24 is supported here from the inside bending roll 25. It ispreferable to have it so centered that skelp 1 of Fig. 4, or 20 of Fig.v1 on roll 25 and on brake 15 lays in a straight line of contact at orin the neighborhood of the place where the seam is welded. This is nottrue for the rest of the circumference, however. The location of rolls2, 3 and 4 is so selected that the same should be true for the part ofthe skelp passing thereover. Here again, as will be more fully explainedhereafter, this does not hold good for the entire periphery.

If the diameter of the coiled pipe in contact with mandrel 24 were thesame as the diameter of the part of the pipe within the live rolls 5, 6and 7, and the brakes 14 were in action, pressure at the seam 33 wouldhave been produced, but that pressure would have quite uniformlydistributed over the entire seam, and with such a distribution ofpressure the welding would have been unsatisfactory. What is needed is apressure for only a little distance beyond the place which has beenalready welded, and this is accomplished by making the diameter of thecircumscribing circle of the rolls 5, 6 and 7 of somewhat smaller thanthe diameter over the mandrel 24. This is indicated in Fig. 1 by therespective positions of skelp'at 19 and at I 20, and is still bettershown by Fig. 5. With and 4. There mag this arrangement, the contact isas shown at 33, Fig. 2 where the upper part of the seam is alreadywelded, contact is made at 33, and there is no contact further down, notbecause the seam is spaced in that part, but because the skelp to the riht of the seam is inside the skelp to the le t of the seam, as shownRofls 2, 3 and 4 may have to be adjusted from time to time, ferentdiameters and also to compensate for wear. This can be done by changingtheir relative positions, i. e. spreading them further apart or bringingthem closer together. To make this possible, tapered frames 46 slidingagainst an invertedly tapered inner mandrel 45. The motion is effectedby nut 48 (equipped with engaging disc 47) working on screw 49, and heldin position by locknut 50. The system of rolls 2, 3 and 4 is carried onthe body 124 which in turn is supported from pin 17 provided with slot18 to take bar 16 (Fig. 5). The outer rolls 5, 6 and 7 are driven bymeans not shown, as throu h gears 21 and 22, and the pressure isreguTated by some means such as counterweights 11 and 12, or the like.The electric current may be supplied by contact shoes 27 and 28.

The drawings, Fi 6, show three rolls, 2, 3

more or less of them, and as a matter 0 fact, a. single roll may be usedinstead. The disadvantage of such an arrangement is its lack offlexibility and adjustabilit for various sizes of pipe.

Instead of straight rolls, such as 4 and 5, concave rolls on the outsideand corresponding convex rolls on the inside, set diagonally, IFnay l geused. The former type is shown in 31,

is there may be a tendency for the skelp to bulge out while oing throughthe rolls 2, 3, and 4, and their outside counterparts, guards 8 havebeen provided, held in position y such means as screws 9 and 10.

The uide 26 can be executed in the form of a ri 40, Fig. 3, possiblywith an overhang as shown, toprevent the skelp from crowding out, or arib without such an overhang as 42, or in the form of a series ofrollers or wheels 43, or finally as a pin 44. V

In ordinary resistance welding the current is applied intermittently,and themaking and breaking of the large currents used places a veryheavy burden upon the generating station, as well as line surges. asmall area is involved at any one time and the work is done at constantpressure which permits to carry on welding if desired with a currentof'constant amperage.

The matter of drive of any of the outside rollers such as 5, 6 or 7, orall of them if that has been elected is a serious one because theirspeed has to be closely synchronized in a given ratio with the speed ofthe bending and the rolls are held in both to make pipe of diflargeratio of speed reduction. Then drive rollers 5, 6 and from the samefluid motor through two universal joints and if necessar a gear, thepurpose of the latter being to a just the speed of rollers 5, 6 and 7 tothat of the fluid motor which may require a gear ratio of perhaps 1:1.2.Such use of universal joints is not new but its combination with a fluidpump and motor is novel.

The movement of rolls 5, 6 and 7 ma be either steady or intermittent asrequire by the character of the welding adopted.

I claim:

. 1; Atube weldin device comprising means for forming a spira tubularmember and imparting a longitudinal movement thereto, a mandrel ada.cent to said forming means in the direction of travel, guiding meansupon said mandrel for maintainingthe edges 0 the spirally wound materialin spaced rewith the generatin line of the tubular member passing througthe roller means'whilst the diameter of the tubular member as formedabout the mandrel is difierent from that passing through the rollers.

Apparatus as set forth in claim 1 wherein the roller means on theoutside of the tubular member are concave.

LEON O'AMMEN.

lation, roller means positioned in the direction of travel of the spiraltube for effecting rotation of the tube and closing under pressure andin abutting relation the edges to be welded, and electrodemeans at theclosure of said edges, for heating the abutting edges and efi'ectingwelding.

2. Apparatus as set forth in claim 1 wherein the relative location ofthe mandrel and the rollers is such that the diameter of the tubularmember in contact with the mandrel is different from the diameter of thetubular member passing throu h the rolls.

3. Apparatus as set orth in claim 1 wherein the rollermeans consist ofmore than one roller on the inside of the skelp and a correspondingnumber of rollers on the outside thereof. I

4. Apparatus as set forth in claim 1 wherein the roller means consist ofmore than one roller on the inside of the skelp and means are providedfor varying the location of said rollers so as to change the diameter ofthe circle circumscribing said rollers.

5. Apparatus as set forth in claim 1 wherein the roller means consist ofmore than one roller on the inside of the skelp and wherein each rolleris mounted on a tapered frame moving upon a tapered mandrel and meansare provided to move all the roller frames to the same extent at thesame time.

' 6. Apparatus as set forth in claim 1 wherein the rollers are so offsetwith respect to the mandrelthat at least in one place the generatingline of the tubular member as formed' about the mandrel coincides whenprolonged

